Unbalanced subtrees in binary rooted ordered and un-ordered trees prefix ID Disanto, Filippo Sémin. Lothar. Comb. 68, B68b, 14 p. (2013)
A word Hopf algebra based on the selection/quotient principle. prefix ID Duchamp, Gérard H.E.; Hoang-Nghia, Nguyen; Tanasa, Adrian Sémin. Lothar. Comb. 68, B68c, 13 p. (2013)
